The reason why Zhu Ying is so familiar with the Ryukyu Kingdom.

This is mainly because of a special place: Diaoyu Island.

In the fifth year of Hongwu, Yang Zai of the Ming Dynasty was sent on a diplomatic mission to Ryukyu. On the way, he discovered and landed on the Diaoyu Islands.

The earliest historical record of place names such as Diaoyu Island and Chiwei Island was "Shunfeng Xiangsong" written in the first year of the Yongle reign.

Since the tribute system began in the fifth year of Hongwu, and after the Ryukyu Kingdom surrendered and established diplomatic relations, the Ryukyu Kingdom has always been the darling of the Ming Dynasty's tribute.

The Ming Dynasty had strict requirements for tribute, not only limiting the number of tributes, such as once every two years or once every three years.

Including tribute roads, there are also specially set up tribute roads.

The number of people is currently limited to 200.

For example, the Tumu Incident in the middle and late Ming Dynasty happened during the Zhengtong period, when the Oirat sent more than 3,000 people to pay tribute to the Ming Dynasty.

Perhaps because there were too many people, the Ming Dynasty did not reward them as usual.

It was precisely because the "reward was not in accordance with the rules" that the Oirat Mongols considered this to be an impolite and provocative act, which led to the Tumu Incident the following year.

The current Ryukyu Kingdom is backward and poor, and is subservient to the Ming Dynasty and obeys its orders.

This attitude won the favor of Zhu Yuanzhang, who gave many preferential treatment to the Ryukyu Kingdom.

Because of its backwardness and poverty, the Ryukyu Kingdom did not have the ability to build seagoing ships, so the Ming Dynasty directly sent ships.

However, due to the lack of tools to maintain ships, the Ryukyu Kingdom's ships were damaged many times after arriving in the Ming Dynasty, which made it impossible to return and the kingdom had to ask the Ming Dynasty for help.

The Ryukyu Kingdom also had unique local specialties. Due to its volcanic topography, the Ming Dynasty mainly obtained military supplies such as sulfur for making gunpowder and horses for land transportation from it.

Some Southeast Asian products, including some hematite, pepper, and frankincense, also appeared in the tribute materials to the Ming Dynasty.

The Ryukyu Kingdom is not unified now, but is divided into three countries: Sannan, Zhongshan, and Sanbei.

Because the country was too poor, when paying tribute, envoys from the three countries set out together.

In order to suppress collusion between Japanese pirates and residents in coastal areas, the Ming Dynasty implemented a maritime ban policy.

After the implementation of the maritime ban, the Ming Dynasty was faced with the problem of finding a fixed overseas trade channel that could replace local merchants in providing the Ming Dynasty with products from various countries.

Among the numerous tributary states, Zhu Yuanzhang chose Ryukyu, which had a special geographical advantage, making Ryukyu the only transit point for maritime trade connecting the Ming Dynasty with East Asia and Southeast Asia.

This means that the Ming Dynasty gave the profits that originally belonged to Ming merchants to Ryukyu.

This is also the reason why throughout the entire Ming Dynasty, from the beginning to the end, it was always severely attacked by Japanese pirates.

Among them, the coastal smugglers lost their maritime trade interests and could only recover them by colluding with the Japanese pirates.

Zhu Yuanzhang and Ru Hong were naturally very clear about the situation of the Ryukyu Kingdom.

Ru Hong frowned and said, "Wakoku is like Ryukyu, a small country with few people, poor land, and far away from the East China Sea. What's the point of conquering it?"

"Now that the Ming Dynasty is supporting Ryukyu, we can make Ryukyu fight against Japan in the future. After containing them, the threat of Japanese pirates will naturally be eliminated."

Since His Majesty was here, Ru Hong did not hide anything and directly expressed her thoughts in the court.

The main purpose of the current support and preferential treatment for Ryukyu is to allow Ryukyu to grow and replace Japan's position.

This policy was indeed well implemented. Later, Ryukyu once suppressed Japan in comprehensive national strength, had developed maritime trade, and was known as the bridge between all nations.

As a vassal state, Ryukyu was extremely loyal to the Ming Dynasty, or in other words, it was always loyal to the entire Chinese land.

It became a vassal state in the fifth year of Hongwu and lasted for five hundred years. Even after the demise of the Ming Dynasty and the accession of the Qing Dynasty, it did not stop paying tribute.

It was not until the end of the Qing Dynasty that Japan forced the Ryukyu Kingdom to stop paying tribute to the Qing Dynasty and to adopt the Japanese era name instead.

He then announced that the Ryukyu Kingdom would be abolished and prefectures would be established, completing the so-called "Ryukyu Disposition", forcibly merging Ryukyu into Japan and establishing Okinawa Prefecture. Thus, the Ryukyu Kingdom was destroyed.

After listening to Ru Hong's meaning, Zhu Ying pondered for a moment and then told her the news that there were mountains of gold and silver in Japan.

However, this not only failed to attract Ru Hong's favor, but instead made her subconsciously want to sneer.

However, Ru Hong soon realized that the person sitting next to her was His Majesty, so she quickly suppressed her sneer, and only her facial muscles twitched.

Then he said, "Mr. Zhu, please don't be surprised. I once met Zhao Liangbi, the Mongol envoy, and I wrote down his three years in Japan. There is no mountain of gold and silver like what you said."

Hearing this, Zhu Ying felt a little embarrassed.

He had no impression of Zhao Liangbi's diplomatic mission to Japan, and thought that the Ming Dynasty had no understanding of Japan at all.

I subconsciously looked at the old man, only to see him turn his head away.

Obviously, the old man is also aware of this matter.

Zhu Yuanzhang was well-read. When he was humiliated by Japan, he ordered the collection of all records about Japan. He was not as unfamiliar with Japan as Zhu Ying imagined.

The reason why Zhu Yuanzhang did not directly refute Zhu Ying was that he considered the face of his eldest grandson and felt that directly refuting the question would hurt his grandson's self-esteem.

Ru Hong was extremely suspicious of Zhu Ying, so naturally she would not care about so many things.

Iwami Ginzan was not discovered until the end of the Mongol Yuan Dynasty, and mining began there.

Moreover, due to the underdeveloped surveying technology, the Iwami Province in the current Japanese territory does not know that the Iwami Silver Mine has such a large reserve.

Two hundred years later, during its heyday from the 16th century to the first half of the 17th century, Japanese silver accounted for about one-third of the world's silver production, most of which came from Iwami Ginzan.

Among them, there are not only silver mines, but also chalcopyrite, pyrite, galena and other mineral veins were discovered during the development.

After the embarrassment, Zhu Ying pondered for a moment and said, "Minister Ru, you may not know, but I have received news from overseas merchants that a huge silver mountain has been discovered in Iwami Province within the borders of Japan."

"Among the foreign merchants, there are those who are good at exploring mineral veins. They initially determined that the silver content of the mine is extremely huge, shocking, and the most they have ever seen in their lives."

When Zhu Yuanzhang heard this, a glimmer of understanding flashed in his eyes.

He finally understood why his eldest grandson was so concerned about the conquest of Japan. It turned out to be because of the discovery of the silver mine.

Zhu Yuanzhang frowned slightly. After all, his eldest grandson was still confined to the identity of a businessman and was too focused on profit.

But how can a mere silver mountain be compared with the silver mountains in the Ming Dynasty?

Thinking of this, Zhu Yuanzhang couldn't help but ask: "Grandson, tell me in detail, how much silver do you estimate that silver mountain can produce?"

Zhu Ying said calmly: "The Iwami Silver Mine in Japan is enough to support the Ming Dynasty for hundreds of years."

Hearing this, Ru Hong froze.

Zhu Yuanzhang even stood up and asked, "Grandson, do you take this seriously?"

Zhu Ying replied calmly, "Of course it is true. I sent my confidant to confirm it several months ago. It is absolutely true."

"Even the confidants came back to report that the reserves of the silver mountain are higher than the previous estimates."